Skullclamp is especially strong with Kykar, Wind's Fury in play, because casting the Skullclamp triggers Kykar, creating a 1/1 body that can be equipped with the Skullclamp
Grist, Voracious Larva / Grist, the Plague Swarm The cost of opportunity to include Grist, Voracious Larva is very low, as its only a 1-drop with deathtouch
Powered up by the absurd mana that Gaeas Cradle can generate, Fiend Artisan even helped spawn a new archetype in the Eternal formats: Cradle Control
Muzzio was a great way for R&D to design a new Arcum without making it busted he is powerful in his own right but there is a still a randomness to your artifact selection which nerfs most combo shenanigans
Ugin, the Ineffable gives you a major discount on all colorless spells (which is all of them for you) and gives you the ability to directly get rid of permanents